The present invention relates to a pneumatic tire, more particularly to a tread pattern suitable for studless tires, comprising shoulder blocks provided with at least one protruding part capable of improving cornering performance and behavior in critical cornering on snowy/icy roads.
Pneumatic tire improved in running performance on snowy/icy roads and steering stability on dry roads are always desired.
It has been known to increase rigidity of land portions of the tread portion of a tire on the inside of a vehicle rather than on the outside of the vehicle in order to improve cornering performance on snowy/icy roads and dry roads.
Also it has been known to provide for such tread portion with
sipes extending in tire axial directions as well as sipes disposed near the tread edges to extend in the tire circumferential direction, or
a so called square shoulder in which an angled corner is formed between the tread surface and sidewall surface in order to increase the edge effect in the tire axial direction and thereby to further improve the cornering performance on snowy/icy roads.
In such tires, however, there is a problem such that, during cornering on a snowy/icy road, when exceeds a critical cornering speed, a sudden side skid is very liable to occur, and if once such side skid occurs, it is difficult to get road grip again in a short time, and the critical behavior becomes unstable.